import numpy as np
from scipy 
xvals = np.arange(100)
sig = 10.
A = 1
x0 = 50
yvals = A * np.exp(-0.5 * ((xvals - x0)/sig)**2)

data = yvals + np.random.randn(len(xvals))*0.1

ldata = np.log10(data)

guess = {}
guess['A'] = data.max()
guess['x0'] = xvals.mean()
guess['sig'] = 1
